This invention relates to a device which separates various fluid phases including immiscible liquids, e.g., oil and water; gas/liquid phases, e.g., air and oil; and three phase compositions, e.i., gas/liquid/solid, e.g., air/oil/metal particles. One example of a particularly useful separation is in a lubricating system for a gas turbine engine. Another example of a useful separation is in chemical processing in which chemical compositions are handled. Such separation systems are also applicable for transmission systems in general, and aircraft power transmissions in particular. A phase separator of this type may be combined with a particle detection system of this type which monitors certain metal particles which are normally generated by wear or mechanical problems, and which become suspended in the lubrication oil during the course of operation.
Engine lubricating systems, transmissions systems and other like systems agitate their fluids, e.g., oil and ingressed gas, e.g., air, by design, to prevent seal leakage. The result is the forming of a two phase air/oil mixture. Such dilution of the oil is obviously undesirable since it results in less oil coming in contact with the surfaces requiring lubrication thereby diminishing the lubricating effect of the oil. Other effects include increasing the necessary size of a piece of equipment, e.g., a reservoir or a heat exchanger. Additionally, the cooling effect of the oil is substantially reduced by such entrained air and may increase the probability of overheating causing accelerated wear.
Cyclonic separators for removing entrained air from oil are known in the prior art. One such device is disclosed in U.S. Pat. No. 4,282,016, issued Aug. 4, 1981, to Thomas E. Tauber, et al entitled "Gas and Failure Particle Separator System." This invention discloses a separator system combined with a particle detector wherein the oil and air entered through the top side of the device, and oil exits from the bottom of the device while the separated air exits from the top. The use of a fixed shroud is also disclosed. Cyclonic debris separators having combined filters for removing wear particles are known and such a device is disclosed in U.S. Pat. No. 4,188,443 issued to Thomas E. Tauber on Apr. 22, 1980.
A fixed shroud used in the separation of the liquid and the air is disclosed in Thomas E. Tauber's et al U.S. Pat. application Ser. No. 708,003, filed 03/04/85. This art discloses a shroud extending downward and enclosing a filter. As the oil and air mixture enter the housing tangentially via an inlet, the heavier oil coalesces outwardly and downward passed the shroud. After the oil reaches the bottom edge of the shroud, it then proceeds upwards under the shroud and flows into a filter. The advantage of the shroud is it substantially reduces the possibility of the passage of any air through the filter.
However, the previously described shroud's efficiency depends, in part, on the location of the interface between the liquid and gas phases. When the interface does not generally coincide with the downward wall of the fixed shroud, the efficiency is less than desirable. Also, the prior art does not disclose an adjustable discharge area for either outlet.